Complete replacement kit for V6 and V8 MerCruisers. The engines cooling system components take a beating. Constantly heat cycled and exposed to salt water and fresh water, these parts corrode at a much faster rate than other engine parts. Sierra thermostat housings are engineered to match OEM housings to ensure technicians and boaters the fit and function will be to factory specifications. Each kit includes the necessary gaskets, plugs and spacers to complete the installation. Mating surfaces have been CNC machined to eliminate additional preparation. For an out of the box solution to damaged or corroded thermostat housings count on Sierra. Key Features Engineered to meet or exceed OEM specifications Kit includes Housing, plugs, gaskets, and spacers required to complete installation Cast iron construction Backed by SeaStar Solutions Limited Two-Year Warranty Sierra Part Number 18-1994 Application Table ApplicationOEM Part NumberGLM13230Mallory9-42502MerCruiser Sterndrive87290A4OscoMC552-SBThe Sierra Engine Parts SelectorIn addition to thermostat housings, we offer a wide variety of other engine parts manufactured by Sierra. To see if we have the part you need, see ourEngine Parts Selector, where you can search by engine make, serial number and model or year of manufacture.